Mining apparatus



DMW

11 Sheets-Sheet l J. F. JOY

MINING APPARATUS Filed May lO, 1935 ll Sheets-Sheet 2 www J. F. JOY

MINING APPARATUS Filed May lO, 1955 `Bam. 21, 1941.

Jan. 21, 1941. y J, F, JOY

MINING APPARATUS 11 sheets-shea 5 Filed May lO, 1935//////////M/////////// \Amwwm m\ [h ven far: c/aesezEf/ay y wey Jan. 21,1941. J. F. JOY 2,229,087

` MINING APPARATUS Filed may 1o, 1935 11 sheets-sheet 4 Jam 2l, 1941- J.F. .JOY 2,229,087

MINING APPARATUS FiledMay l0, 1935 11 SheetS-Sheeb 5 Jan. 21, 1941. J.F. JoY 2,229,087

MINING APPARATUS Filed May 1o, 1955 11 sheets-sheet e was / Alim y'444mm' uyan. 21 1941. J. F. JOY

MINING APPARATUS Filed May lO, 1935 ll Sheets-Sheet '7 Jan. 2l, 1941.

J. F. JOY

MINING APPARATUS Filed May l0, 1935 11 Sheets-Sheet 8 arf Jfan. 21,1941. .1. F. .JOY

MINING APPARATUS Filed May l0, 1955 ll Sheets-Sheet 9 Jan. 21, 1941. 1,F, JoY 2,229,087

MINING APPARATUS y Filed May lO, 1955 l1 Sheets-Sheet Vl0 All/WM Janazl,1941. L F JOY MINING APPARATUS 11 Sheets-Sheet lll Filed May lO, 1935Patented Jan. 21, 1941 UNITED STATS FATNT @FlC MINlING APPARATUSMassachusetts aspiration any ic, i935, serial ntfzasae 29 Claims.

This invention relates to mining apparatus, and more particularly hasreference to improvements in coal mining apparatus for cutting keris ina coal seam at various locations to suit diierent mining conditions.

An object of this invention is to provide an improved coal miningapparatus which is extremely exible in operation and provides an eX-tremely wide range of cutter adjustment. Another object is to provide animproved coal mining apparatus having improved adjustable supportingmeans for the kerf cutter and improved nerf cutter driving means. Afurther object is to provide an improved pivotal. mounting for the kerfcutter driving motor and an improved turntable structure for the drivingmotor mounting. Yet another object is to provide an improved truckpropelling mechanism for driving the truck wheels to propel theapparatus along the mine tracliivay through a wide range of relativelylow cutting speeds and a relatively high transport speed. A furtherobject is to provide improved hydraulic operating means for variousmechanisms of the apparatus, together with an improved hydraulic fluidsystem, embodying improved liquid pressure supply and control means.Still another object is to provide improved hydraulically operatedmechanism for adjusting the elevation and lateral position of the kerfcutter, .for rotating the kerf cutter into horizontal and verticalcutting planes, and for tilting the kerf cutter into cutting planesrelatively inclined with respect to the horizontal and vertical. Stillanother object is to provide an improved hydraulically operated andcontrolled cable reel for the power conductor cable and an improvedhydraulically controlled braking means for the apparatus. Yet anotherobject of this invention is to provide an improved coal mining apparatusof an extremely flexible character whereby the korf cutter may bepositioned into any desired cutting the parts oi the apparatus beingarranged in an extremely compact whereby an apparatus extremely low inheight is attained.

These and other objects and advantages of the inventiin will, however1hereinafter more fully appear.

ln the accompanying drawings there are shown for purposes ofillustration one form and a modification thereof which the invention mayassume in practice.

in these drawings,

.1. and 3, taken together, show in plan a preferred illustrative form ofthe improved mining apparatus, the top plate being broken away to showportions of the internal mechanism.

Figs. 2 and 4, taken together, show the ini proved mining apparatus inside elevation, a portion of the side plate being broken away to 5 showportions of the internal mechanism.

Fig. 5 is an enlarged view in longitudinal section taken substantiallyon line 5-5 of Fig. 1.

Fig. 6 is an enlarged detail sectional view taken on line 6 6 of Fig. 5.10

Fig. 7 is a detail sectional View taken on line '1 -'l of Fig. 6.

Fig, 8 is an enlarged View in longitudinal section taken on line ql-S ofFig. 1.

Fig. 9 is an enlarged horizontal sectional view taken on line t-e ciFig. 2 showing the transmission mechanism.

Fig. 10 is a longitudinally extending vertical sectional View taken online llllll o1 Fig. 9.

Fig. ll is a detail sectional view taken on line ll-il of Fig. 9. f

Fig. 12 is a cross sectional view taken on line lf2-lt of Fig. 10.

Fig. 13 is a horizontal sectional view taken on line lil-i3 of Fig. 5.25

Fig. i4 is a cross sectional view taken on line lll-i4 of Fig. 10.

Fig. l5 is a detail sectional View taken on line l5-l5 of Fig. 9.

Fig. 16 is an enlarged cross sectional view taken o on line it-lt ofFig. l.

Fig. 17 is a detail horizontal sectional view taken on line il--l'l ofFig. 16.

Fig. 18 is a view in longitudinal section of one of the arm swingingcylinders. 35

Fig. 19 is an enlarged View in longitudinal section taken on line l9-l9of Fig. 3.

Fig. 20 is an enlarged cross sectional view taken on line Zit-2t of Fig.3.

Fig. 21 in a detail horizontal sectional View taken on line tl-Zl ofFig. 20.

Fig. 22 is an enlarged View in longitudinal seotion taken on line 22--92of Fig. 3.

Fig. 23 is an enlarged longitudinally extending vertical sectional viewtaken on line 23--23 of Fig. 3.

Fig. 2t is a horizontal sectional view taken on line it- 2li of Fig. 22.I

Fig. 25 is a diagrammatic view showing the im- 50 proved hydraulicsystem.

Fig. 26 is a detail plan View showing the pump control means.

Fig. 27 is a cross sectional View taken on line 21-27 oi Fig. 26.

` extremely Fig. 28 is a cross sectional view taken on line 28-28 ofFig. 26.

Fig. 29 is a detail sectional View taken on line 29-29 of Fig. 28.

Fig. is a longitudinal sectional view taken on line 39-39 of Fig. 26,showing the pump structure.

Fig. 3l is a longitudinal sectional view taken on line 3 I-3I of Fig.26, showing the pump structure.

Figs. 32 and 33 are views similar to Figs. 3 and 4 respectively showinga modified form of construction.

Fig. 34 is an enlarged View in longitudinal section taken substantiallyon line 34-34 of Fig. 32.

In the preferred illustrative embodiment of the invention shown in Figs.l to 31, inclusive, there is shown a coal mining apparatus of theso-called universal type having an improved adjustable supportingstructure for the kerf cutter whereby kerfs may be cut in a coal seam atany desired location to suit different mining conditions. This improvedcoal mining apparatus generally comprises a self-propelled portable baseI, a horizontal turntable 2, a vertically swingable arm structure 3, arotatable head 4, a swingable cutter support 5 and a kerf cutter 6. Theportable base I is herein in the form of a truck frame 'I of an lowcompact design mounted on wheels 8 adapted to run along a mine trackway9 laid on the mine oor. This truck frame has a forwardly projectinghorizontal frame portion I0 supporting, in a relatively low positionbelow the top of the truck and in advance of the front truck wheel axes,an annular frame II on which the turntable 2 is mounted for rotationabout a vertical axis with respect to the truck frame, the turntableaxis being located on the truck frame a substantial distance in advanceof the front truck wheels, thereby enabling the turntable structure tobe mounted on the truck frame in an extremely low position. The annularframe portion II of the truck frame is in the form of a bearing annulusand supports bearing sleeves l2 in which a cylindrical bearing portionI3 of the turntable is rotatably mounted, the turntable being retainedin position within its bearing mounting by an annular shoulder I4engaging the upper bearing sleeve and an annular retaining plate I5secured as by screws to an annular flange I6 formed integral with thebottom of the cylindrical bearing portion I3 of the turntable. Formedintegral with the cylindrical bearing portion I3 of the turntable andextending upwardly therefrom is a segmental open center frame portion orsegmental flange II, the sides of which support bearing hubs I8.Pivotally mounted on the turntable frame to swing in a verticaldirection with respect to the turntable and extending through the openside of the flangeportion I1, is a yoke-shaped frame portion of the arm3, and the arms I9 of this frame have integral bearing hubs 20 journaledon pins 2| secured within the bearing hubs I8 of the turntable frame.Arranged between the arms I9 of the yoke-shaped frame of the swingingarm 3 and secured to the latter, as by bolts, at the rear end thereof isa motor 22, the motor being mounted to swing with the arm 3 between thesides of the segmental flange portion I'I within the central opening ofthe turntable frame. The rotatable head 4 is journaled in an elongatedbearing sleeve 23 supported within the neck portion of the forwardportion of the arm 3, and the head 4 is rotatable within this bearingsleeve about an axis extending longitudinally of the arm at right anglesto the horizontal axis of arm swing. Secured, as by welding to therotatable head 4 and encircling the latter is an annulus 24 having aflange 25 to which is secured, as by screws, an annular retaining plate26, this annulus and retaining plate cooperating with an annular flange21 formed externally on the outer extremity of the arm 3 for retainingthe rotatable head in position on the arm in the manner shown in Fig.19. As shown in Fig. 22, fixed to the outer extremity of the rotatablehead 4 at 28 is a frame 29 to which is secured, as by bolts, ayoke-shaped frame 3U. The swingable cutter support 5 has lateraltrunnions 3l, 3| journaled in bearing sleeves 32 supported by annularbearing supports 33 formed on the arms 34, 34 of the yoke-shaped frame39, the support 5 being swingable with respect to the frame 39 and head4 about an axis arranged at right angles to the aXis of rotation of thehead. The kerf cutter 6 is in the form of an elongated plane cutter bar35 having mounted for circulation in a guideway 36, formed about itsmargin, an endless cutter chain 31. Suitably secured to the bar 35 andSupporting the latter is a bar hanger 38 having an annular bearingportion 39 journaled on bearing sleeves 49 supported by an annularportion 4I of the swingable cutter support 5. The bearing portion of thebar hanger is retained in position on the support 5 between an annularflange 42 formed on the support and a detachable retaining plate 43secured, as by screws, to the frame 44 of the swingable support. It willthus be seen that the kerf cutter may swing with respect to the cuttersupport 5 about an axis perpendicular to the support pivot axis. Themeans for locking the kerf cutter in its different angular positionswith respect to the swingable support comprises a locking pin 45slidably mounted in a bore in the bar hanger and insertible in any oneof a number of locking openings 46 formed in lateral bosses 47 integralwith the annular bearing portion 39 of the bar hanger. The pin is urgedtowards its locking position by a coil spring 43, and a suitable camlever means 49 is provided for moving the pin into its releasedposition.

The motor 22 is herein preferably of the reversible electric type havingthe axis of its power shaft 59 alined with the axis of rotation of thehead 4 and the longitudinal axis of the arm 3, and the drivingconnections between the motor power shaft and the kerf cutter comprise,as shown in Fig. 19, a coupling hub 5I keyed to the motor power shaftand journaled in a ball bearing 52 supported by the front motor head 53.Secured, as by screws, to this coupling hub is a coupling member 54having splined connection with the rear end of a transmission shaft 55arranged with its axis coinciding with the longitudinal axes of the armand the axis of rotation of the head 4. This shaft extends through thearm neck portion and is journaled in a ball bearing 56 supported withina head member 51 secured within the bore of the tubular frame 58 of therotatable head 4. Keyed to the outer end of the transmission shaft 55,as shown in Fig. 22, is a bevel pinion 59, the hub of which is journaledin a ball bearing 60 supported within a head portion 6I integral withthe yoke-shaped frame 39,

and, as shown in Fig. 24, this bevel pinion meshes with a bevel gear 62journaled on a shaft 63 secured within the arm 34 of the yoke frame 39.The bevel gear 62 meshes with a bevel gear 64 keyed to a shaft 65journaled Within ball bear- LI I.)

a naled a guide pulley 39.

ings lill supported Within the frame 3|) and arranged with its axisalined with the axis of swinging movement of the cutter support 5. Fixedto the shaft S5 is a bevel gear B1 meshing with a bevel gear 68connected through a friction safety clutch 63, of the multiple disctype, to a shaft lll, the latter `being journaled in ball bearings illsupported within the swingable support 5. The hubs of the bevel vgear 68are journaled in bearings 12 and 13 supported respectively by the shaft'lll and the frame 44 of the cutter support 5 so that when the clutch 69slips, due to overload, the bevel gear may rotate with respect to theshaft 10. Keyed to the outer extremity of the shaft lll Vis a chainsprocket 14 for engaging and driving the endless cutter chain 3l'. Itwill thus be seen that the transmission connections between the motorand cutter chain are so arranged with respect to the axes of the varioussupports that the cutter chain may be driven irrespective of theadjusted position of the arm 3, the head l and cutter support 5.

Hydraulically operated means is employed for swinging the cutter support5 about its pivot with respect to the frame 33, comprising a cylinder 15pivotally mounted 'at its rear end at 1E on pivot pins supported bybrackets 11 formed integral with the annulus 23 of the rotatable head 4.Reciprocably mounted in the cylinder 15 is a piston 18 having its pistonr'od 13 extending forwardly through the packed front head 8l] of thetilt cylinder and pivotally connected by a pin 8| to the swingablecutter support 5, the pin 8| being mounted in projections 83 formedintegral with the frame Ml of the cutterl support. The hydraulicallyoperated mechanism for rotating the Il with respect to the arrn 3comprises, as shown in Figs. 3, fl, 19, 20, 2l and 23, a pair ofhydraulic cylinders 3d, 84 supported within brackets 35 secured to theopposite sides of the frame of the arm 3, and each containing areciprocable piston 33 (see Fig. 23) having a rearwardly projectingpiston rod 81, Each of these piston rods carries a bracket 33 on whichis jour- Passing around these pulleys 39 are cables (lll, 3l) eachanchored at one end at 3| to the frame of the arm 3, the cables passingfrom the pulleys 89, 83 around inclined pulleys 33, 32 journaled onbrackets secured to the arm frame, and the cables have theirintermediate portions wrapped around a drum 33 formed integral with theretaining annulusI Ell of the head 4l, the opposite ends of these cablesbeing secured at 3d to the frame of the rotatable head fl. The means forlocking the rotatable head i. in its adjusted positions with reto thearm comprises a sliding locking pin mounted in a guideway 96 formed inthe arm frame, and this pin is adapted to project in any one of a seriesVof apertures 91 formed in the frame ci the head Il. The means foroperating this locking pin comprises a cylinder 33 having its front head39 secured to the arm frame. This cylinder contains a piston I ill!having a forwardly projecting piston rod lill secured to a member Themember .|33 `has an opening receiving a pin E33 secured to the lockingpin 35. Arranged within the cylinder 93 and interposed between the rearcylinder head and the piston is a coil spring |34 for urging the lockingpin into its locking position. Hydraulic pressure is `adapted to besupplied to the opposite end of the cylinder to act on the opposite sideof the piston for moving the piston rearwardly to release the lockingpin from the head. Hydraulic means is provided for swinging the arm 3relative to the turntable, comprising a pair of hydraulic cylinders'lull, |35, mounted to swing in vertical planes andfeach containing, asshown in Fig. 18, a piston |35 having its piston rod lill pivotallyconnected at |33 to projections 33 formed integral with the yarm frame.The rear -ends of the cylinders are pivot/ally connected at lll) to abracket formed integral with the turntable frame. It will thus be seen.that when hydraulic pressure is supplied to the `cylinders |35, the arm3 may be swung upwardly `and downwardly with respect to the turntable 3,`as desired. The hydraulic means for rotating the turntable 2 relativeto the truck :l1-aine comprises, `as shown in Figs. l, 2, 5 and 8, apair of hydraulic cylinders H3, H3 secured within the truck frame andarranged in longitudinal parallel relation at 'opposite sides of thetruck frame in the manner shown in Fig. 1. These `cylinders each containa piston (see Fig. 3,), each having a rearwardly projecting piston rod`|i`5 `extending rearwardly through the packed rear head Vi it of thecylinder. Secured to the rear lend of each of the piston rods ||5 is a'bracket M1 on which is journaled a pulley IIB. I

Cables lil, H9 each have an end fastened at |20 to the truck frame andpass around the pulleys 1B, portions `of the cables extending from thepulleys i3 forwardly through openings in the truck frame aroundhorizontal pulleys |2| v journal-ed, as :shown in Fig. 16, in a mannerto be later' described, the opposite end portions of the cablesextending from the pulleys |2| around segmental guiding groove |22formed about the rim of the .frange portion of the turntable frame, f

and these cables are secured at their opposite ends `at |1233 to theturntable frame. It will thus be seen that when .hydraulic pressure issupplied to one or the other of the cylinders H3, the cablesI me f vbeoperated to swing the turntable 2 in one dii'eftion or `the other aboutits axis with respect to the truck. The means for supplying hydraulicpressure to the various hydraulic cylinders above fdc-.scribed will belater described.

Now referring to the improved mechanism for driving the truck wheels topropel the apparatus along the mine trackway through a wide range of lowcutting speeds and at a high transport speed, it "will be noted thatmounted within the truck frame at the rear of the turntable with itsaxis horizontally disposed and extending longitudinally `of the truckframe is a motor |26 herein preferably of the reversible electric typehaving its power shaft |21 connected by a flexible coupling v|28 to alongitudinal shaft |23. This shaft is journaled 'in bearings supportedwithin a gear housing |33 arranged within the truckframe, and has fixedthereto at its forward end a spur pinion |3| meshing with a large spurgear |32, herein the high speed terminal gear, journaled on alongitudinal shaft |33 herein arranged parallel with land below theshaft |23 and likewise suitably journaled within the gear housing |30.The gear 33 is connectible by a multiple disc clutch` |34 to the shaft|33. gear `|32 is a spur pinion 35 meshing with a large spur gear |33fixed to a longitudinal shaft |31 arranged parallel with the shaft |29,|33 and likewise `suitably iournaled within the gear housing. Fixed tothe shaft |31 is a spur pinion |38 meshing with a large spur gear |39,herein the low speed terminal gear, journaled on the shaft |33 andconnectible by a multiple disc clutch |40 to the shaft |33. Keyed to therear end of the shaft |33 is a bevel gear |4| meshing with re- Formed onthe hub of the verse bevels |42 and |43 journaled on a horizontal shaft|44 herein arranged at right angles to the shaft |33 and suitablyjournaled within the sides of the gear housing. The bevel gears |42, |43are connectible by multiple disc clutches |45 and |46, respectively, tothe shaft |44. The operating means for the clutches |45, |46 comprises aclutch applying collar surrounding the shaft |44 between the bevel gears|42 and |43, and engaging this collar is a pivoted shipper yoke |48connected at |49 to an operating rod |50. The outer end of thisoperating rod is pivotally connected at to a lever |52 in turn pivotallyconnected at |53 to a piston rod |54 of an operating piston |55contained in the horizontal hydraulic cylinder |56. This cylinder hasits outer head |51 secured to a bracket |58 projecting from the adjacentside of the truck frame. When hydraulic pressure is supplied to thecylinder |56, the piston |55 may be moved in one direction or the otherto apply one or the other of the clutches |45, |46, thereby to eifectrotation of -the drive shaft |44 selectively in either of oppositedirections. Fixed to the opposite ends of the shaft |44 are chainsprockets |59 connected by endless chains |60 to sprockets |6| xed tothe truck wheel axles. The mechanism for operating the high and lowspeed disc clutches |34, |40 will now be described. Formed on the rearface of the low speed terminal gear |39 is a cam |65 with which engagesa plunger |66 guided in a bore |61 formed in the gear housing. The rearend of this plunger is pivotally connected at |68 to a lever |69 in turnpivotally connected at |10 to a rod |1|. The lever |69 is pivotallymounted by trunnion blocks |12 on an adjusting rod |13, the trunnionblocks having convex surfaces engaging the cylindrical periphery of therod |13, and when inthe position shown in Fig. 10, abutting a collar |14xed to the rod |13. A shipper yoke lever is pivotally mounted at |16 andengages a clutch applying ring |11 surrounding the shaft |33 between thehubs of the gears |32, |39 in the manner shown in Fig. 13, and thisshipper lever |15 is pivotally connected by trunnion blocks |18 to therod |1|, these trunnion blocks having concave surfaces slidinglyengaging the cylindrical rod surface. Threaded on the forward end of therod |1| is a nut |19, and encircling the rod and engaging the nut is awasher |80. Surrounding the rod I1| and acting between a nut |8|threaded to the rod and a washer |82 is a coil spring |83, this springholding the trunnion blocks |18 of the yoke lever against the washer|80. The operating rod |13 is mounted for axial movement within the gearhousing and is splined at |84 against rotation, and the rearwar-dportion of this rod is threaded at |85 for threaded engagement with anut |86 formed within the hub of a worm wheel |61. Meshing with thisworm wheel is a worm |88 fixed to an operating shaft |89 having anoperating handle |99. It will thus be seen that when the worm gearing|88, |81 is rotated, the rod |13, through the nut and threads, is movedaxially to vary the location of the fulcrum pivot of the lever |69. Whenthe gear |39 is rotated, the cam |65 thereon reciprocates the plunger|66, thereby oscillating the lever |66 about its fulcrum, reciprocatingaxially the rod and through the spring |63 yieldingly loading the clutch|40 at timed intervals. By adjusting the rod |13 axially t0 vary thefulcrum point of the' lever |69, the intervals of application andrelease of the clutch |40 may be varied as desired, it being possible toso adjust the parts as to effect contnuous loading of the clutch, noclutch loading, and any desired intermediate loading of the clutchbetween full load and no load. By moving the rod |13 to the left in Fig.10, the clutch |40 may be entirely released from any inuence of the camoperated mechanism, and the high speed clutch |34 loaded. When the highspeed clutch |34 is loaded, the truck wheels may be driven in either ofopposite directions at a high transport speed from the motor |26 throughthe gearing |3|, |32, shaft |33, bevel gear |4| through one or the otherof the reverse bevels |42, |43 and the chain and sprocket connections|59, |60, |6|. When the low speed clutch |40 is loaded, the truck wheelsmay be driven in either of opposite directions at a relatively lowcutting speed from the motor |26 through the gearing |3|, |32, |35, |96,|38, |39, shaft |33, bevel gear |4|, one or the other of the reversebevels |42, |43 and chain and sprocket connections |59, |60, |6|. Byadjusting the rod |13 to vary the fulcrum point of the lever |69 to varythe intervals of application and release of the low speed clutch |40,the truck wheels may be driven through a wide range of low speedsbetween zero and a predetermined maximum low speed.

A hydraulically controlled truck wheel brake is provided comprising, asshown in Fig. 5, a brake drum |95 keyed to the front truck wheel axleand with which a brake band |96 cooperates. This brake band is made intwo parts pivotally mounted on a link |91 supported by the truck frame.The other end of the upper brake band part is pivotally connected at |98to a lever |99, while pivoted to this lever at 200 is an adjustableturnbuckle link connected to the opposite end of the lower portion ofthe brake band. The upper end of the lever |99 is pivotally connected at202 to a piston rod 203 of a piston 204 contained in a hydrauliccylinder 205 mounted on the truck frame. interposed between the rearhead of the cylinder and the piston is a coil spring 206 for urging thepiston toward its forward position to eifect application of the brake.When hydraulic pressure is supplied to the opposite side of the piston,the parts are moved into their brake releasing position.

Hydraulic jack devices are provided for jacking the apparatus inposition on the trackway during the cutting operation and comprise, asshown in Fig. 16, a pair of hydraulic cylinders 2 0 mounted in parallelvertical relation at opposite sides of the truck frame and eachcontaining a piston 2| having an upwardly projecting piston rod 2|2.These piston rods project through the packed upper heads 2 I3 of thecylinders, and are each provided with a socket 2|4 for receiving a jackpipe 2|5. It will thus be seen that when hydraulic pressure is suppliedto the jack cylinders below the pistons 2| the jack pipes 2 |5 may bemoved upwardly into engagement with the mine roof to jack the apparatusin position on the track rails. The guide pulleys |2| for the cables ofthe turntable rotating means are journaled, as shown in Fig. 16, on thecylindric bodies of the hydraulic anchor jacks.

For supplying motive power to the motors 22 and |26, there is provided acable reel 220 rotatably mounted within the rearward portion of thetruck frame on a horizontal transversely extending axis, the cable reelbeing arranged in a chamber 22| formed in the truck frame between thepulleys and cables ||8, ||9 of the turntable rotating mechanism, asshown in Fig. 1. Wound upon this cable reel is a power conductor cable222 guided by an automatic spooling device 223 arranged on the rear endof the truck frame at the rear of the reel. The cable reel 229 is drivenby a hydraulic motor 224 through a sprocket 225, an endless chain 226and a sprocket 221 fixed to the reel drive shaft. Also rotatable withthe sprocket 221 and driven by the chain 225 is a chain sprocket 229connected by an endless chain 229 to a sprocket 239 fixed to the driveshaft 23| of the automatic spooling device 223.

Now referring to the hydraulic pump and control means, it will be notedthat arranged in a chamber 232 between the cable reel and the rear endof the motor |23 is a tank 233 for containing a liquid, preferably oil,and arranged in this tank is a gear pump 234 driven by the power shaft|21 of the motor |26. This pump is adapted to supply hydraulic pressureto the various hydraulically operated devices of the apparatus. As shownin Fig. 5, mounted on the top of the gear housing |39 for thetransmission gearing is a horizontal valve bex 235 having formed thereina series of horizontal valve bores 239 each containing a balanced typeslide valve for controlling the flow of hydraulic pressure to thevarious hydraulic devices. As shown most clearly in Figs. 6 and 7, thevalve stern 231 of each of these slide valves is provided with slottedsides at 239 with which engage a yoke-shaped member 239, the arms ofwhich engage the flattened sides of the valve stems for preventingrotary motion of the valves while connecting the valves for axialmovement with the members 239. Each of the members 239 is secured to aflat operating bar 249 extending transversely across the top of thetruck frame and guided in grooves 29| formed in the sides of the truckframe, and each end of these operating bars is provided with aconveniently located handie 222 whereby the valves may be operated fromeither side of the apparatus. The gear pump 234 is of the variabledisplacement type comprising a gear chamber 295 containing threeintermeshing gears 225 secured to parallel shafts journaled within thepump casing and to one of which the motor power shaft of the motor |29is connected. Formed in the pump casing are parallel vertical bores 291and 293 containing slide valves 249 and 259 respectively. The valvestems 25| of these valves are each slotted at 252 to receive thebifurcated ends of levers 253 and 254 secured respectively to paralleloperating rods 255 and 255 extending longitudinally forwardly within thetop portion of the truck frame. These rods have fixed thereto levers 251and 25B, respectively, each connected by a pin 259 engaged in a slotformed on depending plate-like projections 299 secured to transverselyextending operating rods 29i and 292 respectively, these rods beingsimilar to the operating rods 299 for the control valves and similarlyguided on the top of the truck frame. When the operating rods 26|, 292are slid in one direction or the other, the slide valves will be slideither upwardly or downwardly within the valve bores of the pump casing.The lower ends of the valve bores 241, 299 communicate with the oilsupply contained in the tank 233, while the upper end of the valve bore241 communicates through a passage 293 with the liquid supply in thetank. The valve bores are connected through passages 264 and 265 withthe intake sides of the pump gears and through passages 296 and 261 withthe discharge sides of the pump gears. The valve bore 241 is connectedto the hydraulic system through a passage 299, while the valve bore 228is connected to the hydraulic system through a passage 269. When thevalve 259 is in the position shown in Fig. 3l, hydraulic pressure mayilow from the supply tank through the valve bore and passage 265 to thepump intake, and the pump discharge is connected through passage 251 andthrough the valve bore past the valve to the passage 269 of thehydraulic system. When the valve 249 is in the position shown in Fig.30, the supply of fluid from the passage 293 to the pump intake passage294 is cut olf, While the pump discharge is connected through thepassage 299 and the valve bore to the liquid supply in the tank. It willthus be seen that when the valves 299 and 259 are in the position shownin Figs. 30 and 3l, the pump is operating at half capacity. When it isdesired to supply the full pump capacity to the hydraulic system, thevalve 249 is slid downwardly from the position shown in Fig. 39 toconnect the intake passage 293 with the pump intake passage 294 and thepump discharge passage 259 with the passage 298 of the hydraulic system,so that at this time both. discharge sides of the pump gears areconnected to supply hydraulic pressure to the system. When the valve 259is slid downwardly from the position shown in Fig. 3l, the passage 265is cut off by the valve while the passage 251 is connected to the liquidtank, and at that time the supply of hydraulic pressure to the system iscut 01T and both discharge sides of the pump gears are connected todischarge back to the tank.

Now referring to the improved hydraulic system shown in Fig. 25, it willbe noted, as above mentioned, that the horizontal valve bores 239 in thevalve box 235 each contain a slide valve, and these slide valves arerespectively designated 229, 21|, 212, 213, 214, 215, 219, 211 and 218.Formed in the valve casing and extending substantially there-across toconnect the opposite ends of the valve bores into communication with oneanother, are parallel passages 219 and 289, respectively, these passagesbeing connected through branched conduits 28| and 282 to a dischargeconduit 293 leading to the liquid supply tank 233. The valve bores areconnected together by a liquid pressure supply passage 294 communicatingwith the valve bores midway between their ends, this passage 234arranged parallel with the discharge passages 219, 289 and likewiseextending substantially across the valve box. The passage 234 isconnected by a conduit 285 with a conduit 286 connected to the dischargepassages 293 and 299 of the pump. Elach of the slide valves is centrallygrooved between end heads, and these grooves at all times communicatewith the liquid pressure supply passage 294. The slide valve 219, whichcontrols the supply of liquid pressure to the turntable rotatingcylinders ||3, ||3, has its valve bore connected through a conduit 281to the forward end of one cylinder ||3 and through a conduit 289' to theforward end of the other cylinder ||3, and the rear ends of thecylinders ||3 are connected through conduits 299 and 299, respectively,and a discharge conduit 29| to the liquid supply tank for conducting anyoil leakage past the pistons back to the tank. The valve 21|, whichcontrols the supply of liquid pressure to the arm swing cylinders |95,|95, has its bore connected through a conduit 292 to a conduit 293communicating with the rear ends of the cylinders 95 and through aconduit 294 communicating with a conduit 295 connected to the forwardends of the cylinders |95. The valve 212, which controls the supply ofliquid pressure to the cutter support swing cylinder 15, has its boreconnected through a conduit 296 to the forward end of the cylinder 15and through a conduit 291 to the rear end of the cylinder 15. The valve213, which controls the supply of liquid pressure to the head rotatingcylinders 84, 84, has its bore connected through a conduit 298 to theforward end of one cylinder 84 and through a conduit 299 with theforward end of the other cylinder 84. The valve 214, which controls thesupply of liquid pressure to the anchor jack cylinders 2|0, 2|0, has itsbore connected through a conduit 390 and a branched conduit 30| to thelower ends of the anchor jack cylinders and through a conduit 302 andbranched conduits 303 to the upper ends of the anchor jack cylinders.The valve 215, which controls the supply of liquid pressure to thesupport lock cylinder 98, has its bore connected through a conduit 304to the forward end of the lock cylinder. The valve 216, which controlsthe supply of liquid pressure to the reel drive motor 224, has its boreconnected by a conduit 305 to the reel motor intake and through aconduit 306 to the reel motor discharge. The valve 211, which controlsthe supply of liquid pressure to the brake cylinder 205, has its boreconnected through a conduit 301 to the forward end of the brakecylinder. The valve v218, which controls the supply of liquid pressureto the clutch operating cylinder |56, has its bore connected through aconduit 308 to the inner end of the cylinder |56 and through a conduit309 to the outer end of the cylinder |56. The supply conduit 286 hascommunicable therewith, under the control of a valve 3|0, a conduit 3||leading to a breaker pad similar to that disclosed in my copendingapplication, Serial No. 700,681, filed Dec. 2, 1933, now matured intoPatent No. 2,163,341, patented June 30, 1989, and this conduit 3|| isconnectible, under the control of the valve 3|0, to a discharge conduit3|2 communicating with the liquid supply tank.

As previously mentioned, the pump 234 may operate at either halfcapacity or full capacity under the control of the slide Valves 249 and250. When the control valves are in the position shown in Fig. 25, allof the various conduits referred to are out of communication with thesupply passage 284 and the discharge passages 219 and 280. When it isdesired to effect turntable rotation in one direction, the valve 210 isslid in a direction to connect the conduit 281 with the supply passage284 and to connect the conduit 288 with the discharge passage 280, andat this time liquid pressure is supplied through the conduit 281 to onecylinder |3 to act on its piston |4 to rotate `the turntable 2, whilethe other cylinder is connected to exhaust. When it is desired to rotatethe turntable 2 in the opposite direction, the valve 210 is slid in theopposite direction to connect the conduit 288 with the supply passage284 and the conduit 281 to the discharge passage 219, and at this timeliquid pressure is supplied through the conduit 288 to the othercylinder I3 to act on its piston ||4 to rotate the turntable 2 in theopposite direction. To effect swinging of the arm structure 3 upwardlyabout its pivot relative to the turntable, the valve 21| is moved into aposition to connect the conduit 292 to the supply passage 284 while theconduit 294 is connected tol the discharge passage 280, and liquidpressure is then supplied through the conduit 292 to the rear ends ofthe cylinders |05 to act on the pistons |06 to move the latterforwardly. The arm structure may be swung downwardly, when the valve 21|is moved to connect the conduit 294 to the supply passage 284 and theconduit 292 to the discharge passage 219, liquid pressure then beingsupplied to the conduit 294 and branched conduits 295 to the forwardends of the arm swing cylinders |05 to effect movement of the pistons|06 rearwardly. The arm structure may be locked in any desired adjustedposition by returning the valve 21| to the position shown to trap theliquid in the cylinders. When it is desired to effect swinging of thecutter support 5 relative to the rotating head 4 in one direction, thevalve 212 is slid into a position to connect the conduit 296 with thesupply passage 284 and the conduit 291 to the exhaust passage 280,liquid pressure then being supplied through conduit 296 to the forwardend of the cylinder 15 to swing the cutter support in one direction. Toeffect swinging of the cutter support in the opposite direction, thevalve 212 is slid into a position to connect the conduit 291 to thesupply passage 284 and the conduit 296 to the discharge passage 219,liquid pressure then being supplied through conduit 291 to the rear endof the cylinder 15. When it is desired to rotate the head 4 relative tothe arm in one direction or the other, the valve 213 may be slid into aposition to connect one of the conduits 298 and 299 to the supplypassage 284 and the other of the conduits 298 and 299 to one of thedischarge passages 219 and 280, thereby to supply liquid pressure to oneor the other of the cylinders 84 of the head rotating means. 'Ihe anchorjacks 2|5 may be moved into anchoring position by sliding the valve 214into a position to connect the conduit 300 with the supply passage 284and the conduit 302 with the discharge passage 280, liquid pressure thenbeing supplied to the lower ends of the jack` cylinders 2|0 to move thejack pistons 2|| upwardly into anchoring position. When it is desired torelease the anchoring jacks, the con-l duit 300 is connected to thedischarge passage 219, while the conduit 302 is connected to the supplypassage 284, thereby to effect downward movement of the jack pistons.When it is desired to release the head lock, the valve 215 is moved to aposition to connect the conduit 304 to the supply passage 384, therebyto supply liquid pressure to the bar lock cylinder 98 to act on thepiston |00 thereof to move the locking pin 95 into its releasedposition. When the conduit 304 is connected by the valve 215 to thedischarge passage 219, the spring |04 of the lock cylinder moves thepiston |00 into a position to effect locking of the head. The reeldriving motor 224 may be operated by moving the valve 216 to a positionto connect the conduit 305 with the supply passage 284, while thedischarge conduit 306 is connected to the discharge passage 280. Toeffect release of the truck wheel brake |95, |96, the valve 211 is movedinto a position to connect the conduit 301 with the supply passage 280,thereby to supply liquid pressure to the forward end of the brakecylinder 205 to move the brake piston 204 into its released position. Toeffect brake application, the conduit 301 is connected by the valve 211to the discharge passage 280, the brake cylinder spring 206 then actingon the piston to move the brake into applied position. To operate one orthe other of the reverse clutches |45, |46 of the truck drive, the valve218 may be moved into a position to connect one of the conduits 308, 309to the supply passage 284 and the other of the conduits 308, 309 to oneor the other of the discharge passages 219, 280, thereby to supplyliquid pressure to one end or lthe other of the clutch operatingcylinder 56.

In the modified form of construction disclosed in Figs. 32, 33 and 34,there is shown a somewhat different form of mounting for the kerfcutters. In this instance, a motor 3|5 has formed on the sides of itscasing bearing supports 3|E mounted on the pivot pins 2| supported inthe bearing bosses i8 of the flange portion of the turntable frame.Secured to the forward end of the motor casing is a support 3H on whichis secured the hanger M8 for the bar 3|!) of the kerf cutter. Keyed tothe forward end of the motor power shaft is a bevel pinion 32) meshingwith a bevel gear 32H journaled within the support 3H and driving a spurgear 322 meshing with a large spur `gear 323 iixed to a shaft 324suitably journaled within the support 3| l. Fixed to this shaft ttul isa chain sprocket 325 which engages and drives an endless cutter chain326 mounted for circulation about the margin of the cutter bar siii. Fortilting the motor casing relative to the turntable to change the anglein altitude of the cutter bar relative to the horizontal, there is ahydraulic cylinder 321 pivotally mounted at 323 on a bracket 329 formedintegral with the turntable frame. rThis cylinder contains a piston 33Hhaving its piston rod 33| pivotally connected at 332 to projections 333projecting rearwardly from the motor casing. When hydraulic pressure issupplied to one end or the other of the cylinder titl, the piston 3,39may be moved in a direction to tilt the cutter bar either upwardly ordownwardly as desired. The cutter bar is swung horizontally in its planeby rotation of the turntable 2. Otherwise this form of the invention issimilar to that above described, and the supply of pressure uuid to thecylinder 32'! is controlled in a manner similar to the various otherhydraulic cylinders above described.

rlhe general mode of operation of the improved mining apparatus is asfollows: The apparatus is propelled about the mine at a high transportspeed under the control of the high speed friction clutch |534. When theworking place is reached and it is desired to insert a horizontal kerfin the coal seam at the level of the mine floor, hydraulic pressure isiirst supplied to the lock cylinder to release the locking pin andthereafter hydraulic pressure is supplied to the proper cylinder dal,dit of the head rotating means to rotate the head fl to move the kerfcutter from the full line position shown in Fig. 4 to the lower dottedline position in that ligure, the supply of liquid pressure to therotating cylinder thereafter being cut oi and the liquid pressure ventedfrom the lock cylinder to again effect locking of the head in position.Hydraulic pressure is then supplied to the proper cylinder of theturntable rotating means to effect swinging of the arm structurelaterally until the tip end of the kerf cutter reaches the right handrib of the entry, the supply of liquid pressure to the rotating cylinderthereafter being cut oil". The operator then starts the motor 22 toeffect rapid circulation of the cutter chain 3l about the margin of thecutter bar 35. The low speed truck wheel drive control clutch It@ isthen applied, thereby to effect propulsion of the apparatus bodily alongthe trackway at a low cutting speed to sump the cutter bar beneath thecoal. When the sumping cut is completed, the low speed truck drivecontrol clutch is released and thereafter the supply of liquid pressurein the brake cylinder is vented to effect application of the brake |95,|96 to hold the apparatus in a stationary position on the trackway.Hydraulic pressure is at the same time supplied to the lower ends of thejack cylinders to move the jacks into anchoring relation with respect tothe mine roof. Hydraulic pressure is then supplied to the properturntable rotating cylinder to effect turntable rotation in a directionto swing the cutter bar across the coal face from right to left untilthe tip end of the cutter bar reaches the left hand rib of the entry,the liquid pressure supply to the turntable rotating cylinder thereafterbeing cut off. The anchor jacks are then released and hydraulic pressureis supplied to the brake cylinder to effect release of the brake. Thelow speed truck drive control clutch IM is then again applied, and uponproper application of one of 'the reverse clutches |45, |46 the truckwheels are driven in a direction to move the apparatus bodily rearwardlyalong the mine trackway at a low cutting speed to withdraw the cutterbar from beneath the coal, thereby to complete the cut beneath lthecoalseam. If itis desired to insert a shear cut in the coal seam,hydraulic pressure is supplied to the lock cylinder to release the headlock and thereafter hydraulic pressure is supplied to the propercylinder of the rotating means for the head 4 to move the kerf cutterfrom a horizontal cutting position into a vertical cutting position, thehead lock thereafter being connected. Hydraulic lpressure is thensupplied to the arm swing cylinders to swing the arm 3 in a verticaldirection relative to the turntable until the tip end of the cutter barreaches the mine roof, the liquid pressure supply to the cylinders HB5thereafter being cut ou. The low speed truck w-heel drive control clutch|40 is then applied to effect propulsion of the apparatus at a lowcutting speed bodily along the mine trackway in a direction to effectsumping of the cutter bar into the coal seam. The anchor jacks are thenmoved into anchoring relation with the mine roof and the truck wheelbrake set. Hydraulic pressure is then supplied to the arm swingcylinders m5 to effect swinging of the arm downwardly to move the kerfcutter downwardly in its yplane to cut a vertical kerf between the mineroof and mine floor. When the tip end of the cutter bar reaches the minefloor, the swinging of the arm is discontinued and the anchor jacks andbrake are released. The low speed truck` drive control clutch It!! isthen again applied, and under the control of one or the other of thereverse `control clutches |lt5, hlt the apparatus is propelled bodilyrearwardly along the mine trackway at a low cutting speed to withdrawthe cutter bar from the coal, thereby to complete the cut. If desiredvertical shear cuts may be made solely by swinging of the arm withouteiiecting sumping and withdrawal cuts as above described. The cutter barmay be swung into different incl-ined positions with respect to thehorizontal and vertical by supplying hydraulic pressure to the supportswing cylinder l5 to swing the cutter support relative to the rotatinghead 4. The cutter bar may be swung in its plane into dierent angularlyrelated positions with respect to the cutter support 5 by releasing thelocking pin 45. It will be evident tha-t by proper adjustment of theturntable, arm, rotating support and cutter support relative to thetruck frame and by swinging the parts in proper position, horizontalkerfs may be cut at any desired location between the mine roof and minefloor, and vertical kerfs may be inserted in the coal seam at anydesired location between the ribs. Also by proper Eli adjustment of theparts, the kerf cutter may be operated to cut kerfs in either rib of theentry. It will also be evident that by varying the location of thefulcrum point of the lever 169 of the low speed clutch operating means,the rate of low cutting feed may be varied, as desired, it beingpossible to drive the truck wheels to propel the apparatus at anydesired low cutting speed between zero and a predetermined maximum lowcutting speed. Further, by varying the position of the control valves269 and 250 of the pump, the capacity of the hydraulic system may bevaried at will. These and other uses and advantages of the improvedmining apparatus will be clearly apparent to those skilled in the art.

While there is in this application specifically described one form and amodification thereof which the invention may assume in practice, it willbe understood that this form and modification thereof are shown forpurposes of illustration and that the invention may be further modifiedand embodied in various other forms without departing from its spirit orthe scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. In a mining apparatus, a portable base, a horizontal turntablemounted on said base and having a central opening, an arm structurepivotally mounted on said turntable to swing in avertical directionrelative thereto, a support mounted on the outer extremity of said armstructure for rotation about the longitudinal axis of said armstructure, a cutter support swingably mounted on said rotatable supporton an axis at right angles to the rotatable support axis, a kerf cuttercarried by said swingable support, and a kerf cutter driving motormounted on the rear end of said arm structure to swing therewithrelative to the turntable and located Within said central turntableopening.

2. In a mining apparatus, a portable base, a horizontal turntablemounted on said base in a relatively low position with its bottomsurface arranged adjacent the bottom surface of said base and having anupstanding frame providing a central opening, the top surface of saidupstanding frame being arranged below the top surface of said base, anarm structure pivotally mounted on said turntable to swing in avertica1l direction relative thereto about a horizontal axis locatedbelow the top surface of said upstanding frame, a revolving supportmounted on the outer extremity of said arm structure for rotation aboutthe longitudinal axis of said arm structure, a cutter support swingablymounted on said revolving support on an axis at right angles to therevolving support axis, a kerf cutter carried by said swingable support,and a kerf cutter driving motor mounted on the rear end of said armstructure to swing with the latter with respect to said turntable andlocated within said upstanding frame opening.

3. In a mining apparatus, a portable base, a horizontal turntablemounted on said base in a relatively low position with its top surfacearranged below the top surface of said base, said turntable having anupstanding segmental frame having at its opposite sides bearing bosseslocated below the top of the turntable and supporting pivot pins, an armstructure pivotally mounted on said turntable to swing in a verticaldirection relative thereto and having at its opposite sides cylindricalbearing portions journaled on said pivot pins, a revolving supportmounted on the outer extremity of said arm structure for rotation aboutthe longitudinal axis of said arm structure, a cutter support swingablymounted on said revolving support on an axis at right angles to therevolving support axis, a kerf cutter mounted on said swingable support,and a motor carried on said arm structure to swing therewith withrespect to said Iturntable for driving said kerf cutter.

4. In a mining apparatus, a portable base, a horizontal turntable onsaid base, said turntable having an upstanding segmental ange providinga central opening, an adjustable supporting structure pivotally mountedon said turntable between the sides of said segmental flange with itsrearward portion arranged in said central flange opening, and a kerfcutter carried by said supporting structure.

5. In a mining apparatus, a portable base, a horizontal turntable onsaid base, said turntable having an upstanding segmental flangeproviding a central opening, an adjustable supporting structurepivotally mounted on said turntable between the sides of said segmentaliiange with its rearward portion arranged in said central flangeopening, a kerf cutter carried by said supporting structure, and a kerfcutter driving motor mounted on the rear end of said supportingstructure to swing with said supporting structure and arranged in saidcentral ange opening.

6. In a mining apparatus, a portable base, a relatively wide, low,compact horizontal turntable mounted on said base in a relatively lowposition below the top of said base, an arm structure mounted on saidturntable between the sides of the latter to swing in a verticaldirection relative thereto about a horizontal pivot located in arelatively low position below the top surface of said turntable, a kerfcutter supported by said arm structure, and means for swinging said armstructure relative to said turntable.

7. In a mining apparatus, a portable base, a relatively wide, low,compact horizontal turntable mounted on said base in a relatively lowposition below the top of said base, an arm structure mounted on saidturntable between the sides of the latter to swing in a verticaldirection relative thereto about a horizontal pivot located in arelatively low position below the top surface of said turntable, a kerfcutter supported by said arm structure, and means for swinging said armstructure relative to said turntable including a cylinder pivotallyconnected to said turntable at a point above the bottom surface of thelatter, a piston contained in said cylinder having a piston rod and apivotal connection between said piston rod and said arm structure.

8. In a mining apparatus, a portable base, traction means therefor, aframe supported on said base in advance of said traction means andhaving an annular bearing portion, a horizontal turntable mounted onsaid annular bearing portion and having an upstanding segmental frame,an arm structure pivotally mounted on the turntable between the sides ofsaid segmental frame to swing in a vertical direction relative thereto,and a kerf cutter supported on said arm structure.

9. In a mining apparatus, a wheeled truck adapted to run along a minetraclway, a low compact horizontal frame on said truck having a portionprojecting forwardly therefrom in advance of the front truck wheels andarranged in a relatively low position with its bottom surfacebelow ahorizontal plane including the truck wheel axes, a horizontal turntablemounted on said projecting frame to turn about a vertical axis located asubstantial distance in advance of the front truck wheels, an armpivotally mounted on said turntable to swing in a vertical directionrelative thereto, and a lserf cutter carried by said arm.

10. In a mining apparatus, a wheeled truck adapted to run along a minetrackway, a low compact horizontal frame on said truck projectingforwardly therefrom in advance of the front truck wheels and arranged ina relatively low position with its bottom surface below a horizontalplane including the truck wheel axes, a horizontal turntable mounted onsaid projecting frame to turn about a vertical axis located asubstantial distance in advance of the front truck wheels, an armpivotally mounted on said turntable to swing in a vertical directionrelative thereto, a cutter support pivotally mounted on the outerextremity of said arm to swing relative thereto about an axis arrangedat right angles to the longitudinal axis of said arm, and a kerf cuttercarried by said cutter support.

11. In a mining apparatus, a wheeled truck adapted to run along a minetrackway, a low compact horizontal frame on said truck projectingforwardly therefrom in advance of the front truck wheels and arranged ina relatively low position with its bottom surface below a horizontalplane including the truck wheel axes, a horizontal turntable mounted onsaid projecting frame to turn about a vertical axis located asubstantial distance in advance of the front truck wheels, an armpivotally mounted on said turntable to swing in a vertical directionrelative thereto, a revolving support mounted on the outer extremity ofthe arm to rotate relative thereto about an axis extendinglongitudinally of said arm, and a lrerf cutter carried by said revolvingsupport.

l2. In a mining apparatus, a wheeled truck adapted to run along a minetrackway, a low compact horizontal frame on said truck projectingforwardly therefrom in advance of the front truck wheels arranged in avrelatively low position with its bottom surface below a horizontalplane including the truck wheel axes, a horizontal turntable mounted onsaid projecting frame to turn about a vertical axis located asubstantial distance in advance of the front truck wheels, an armpivotally mounted on said turntable to swing in a vertical directionrelative thereto, a revolving support mounted on the outer eX- tremityof said arm for rotation about an axis extending longitudinally of saidarm, a cutter support swingably mounted on said revolving support on anaxis at right angles to the axis of the revolving support, and a kerfcutter carried by said swingable support.

13. In a mining apparatus, a truck mounted on wheels adapted to runalong a mine trackway, said truck having a frame provided with anannular bearing portion arranged on the forward lportion of the truckand projecting forwardly in advance of the front truck wheels, aturntable journaled on said annular bearing portion with the top of theturntable disposed below the top of said truck, said turntable having aportion. projecting outwardly beyond the outer periphery of said annularbearing portion, an arm pivotally mounted on said turntable to swing ina vertical direction with respect thereto about a horizontal axislocated inwardly with respect to said outer bearing portion periphery,and motor operated means disposed below the top of said truck forswinging said arm about its pivot relative to said turntable includingextensible adjusting devices extending between said outwardly projectingturntable portion near the bottom of said turntable and the lowerportion of said arm.

14. In a mining apparatus, a truck mounted on wheels adapted to runalong a mine tra-ckway and having a truck frame provided with a forwardannular bearing portion, a turntable mounted in a relatively lowposition cn said annular bearing portion to rotate with respect theretoabout a vertical axis located in advance of the front truck wheels,means arranged above and below said annular bearing portion forjournaling said turntable thereon, said means having a connecting frameextending therebetween and outwardly around said annular bearingportion, an arm structure pivotally mounted on said turntable to swingin a vertical direction with respect thereto about a horizontal axislocated inwardly with respect to said annular bearing portion, a kerfcutter carried by said arm structure, and extensible adjusting devicesextending between said connecting frame near the bottom of saidturntable and the lower portion of said arm structure for swinging thelatter about its pivot.

l5. In a mining apparatus, a portable base, a horizontal turntable onsaid base, said turntable having an annular frame having its forwardportion out away, an adjustable supporting structure pivotally mountedon said turntable between the sides of said annular frame and projectingforwardly through said cut away portion, and a kerf cutter carried bysaid adjustable supporting structure.

16. In a mining apparatus, a low compact horizontal truck framesupported on truck wheels adapted to run along a mine trackway, thewheel base of the truck located substantially at the central portion ofthe truck frame and the truck frame having portions projectinghorizontally forwardly and rearwardly with respect to the truck wheels,the forward projecting portion of the truck frame arranged in arelatively low position and providing an annular bearing frame, ahorizontal turntable journaled for rotation on said annular bearingframe about a vertical axis located a substantial distance in advance ofthe front truck wheels, the top surface of the turntable located belowthe to-p surface of the truck frame, an adjustable supporting structuremounted on said turntable,` and projecting forwardly in advance of thetruck frame, and a kerf cutter carried by said supporting structure.

17. In a mining apparatus, a low compact horizontal truck framesupported on truck wheels adapted to run along a mine trackway, thewheel base of the truck located substantially at the central portion ofthe truck frame and the truck frame having portions projectinghorizontally forwardly and rearwardly with respect to the truck wheels,the forward projecting portion of the truck frame arranged in arelatively low position and providing an annular bearing frame, ahorizontal turntable journaled for rotation on said annular bearingframe about a vertical axis located a substantial distance in advance ofthe front truck wheels, the top surface of the turntable located belowthe top surface of the truck frame, an arm structure pivotally mountedon said turntable to swing vertically with respect thereto and when inhorizontal position located below the top surface of the truck frame,and a kerf cutter carried by said arm structure.

